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Pediatr Emerg Care 2020 Mar 19. Epub 2020 Mar 19.

Pediatric Emergency Medicine, University of Alabama at Birmingham, Birmingham, AL.

Repeated presentations of a rare symptom in a patient should make a physician stop and evaluate for rare conditions. This is a report of a teenager with multiple episodes of rhabdomyolysis and weakness. He was eventually diagnosed as having McArdle muscular dystrophy, or glycogen storage disease type V. Read More

Ophthalmic Genet 2020 02 3;41(1):73-78. Epub 2020 Mar 3.

Department of BioMedical Research, University of Bern, Bern, Switzerland.

: We present a longitudinal clinical characterization of -linked pattern dystrophy in an adult male patient.: A patient affected by McArdle disease (glycogen storage disease type V) and homozygous for the nonsense variant c.148C>T p. Read More

J Inherit Metab Dis 2020 Jul 24;43(4):778-786. Epub 2020 Feb 24.

Copenhagen Neuromuscular Center, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.

Glycogen storage disease type V (GSDV) is a rare inborn error of carbohydrate metabolism. Patients present with exercise intolerance due to blocked glycogen breakdown in skeletal muscle. Introducing alternative fuel substrates, such as ketone bodies (KBs), could potentially alleviate muscle symptoms. Read More

Anaesth Rep 2019 Jul-Dec;7(2):73-75. Epub 2019 Aug 19.

Washington University in St. Louis Missouri USA.

McArdle disease (glycogen storage disease type V) is a rare, autosomal recessive disorder with an incidence of roughly 1:100,000. Despite concern that labour could predispose these patients to muscle damage, there are no evidence-based guidelines for the management of labour and delivery in this population. We describe the case of a nulliparous parturient with both McArdle disease and adenosine monophosphate deaminase 1 deficiency who developed rhabdomyolysis after vaginal delivery. Read More

Acta Myol 2019 Dec 1;38(4):215-232. Epub 2019 Dec 1.

Copenhagen Neuromuscular Center, Department of Neurology, Rigshospitalet, University of Copenhagen, Denmark.

Muscle and lower motor neuron diseases share a common denominator of perturbed muscle function, most often related to wasting and weakness of muscles. This leads to a number of challenges, such as restricted mobility and respiratory difficulties. Currently there is no cure for these diseases. Read More

Acta Myol 2019 Dec 1;38(4):197-206. Epub 2019 Dec 1.

CRIAMS-Sport Medicine Centre, University of Pavia, Voghera, Italy.

The high level of complexity underlying the heterogeneous pathophysiology of neuromuscular diseases is a fundamental limiting factor in understanding the role of physical activity in their onset and/or clinical evolution. To overcome this difficulty, it is essential to rely on and deep knowledge of the aetiology and on the physiological adaptations to physical exercise, in order to predict how they can impact on the clinical history of each disease. This paper illustrates the possible strategies of intervention in some neuromuscular disorders, through the analysis of their supposed pathogenic mechanisms. Read More

Int J Mol Sci 2019 Nov 25;20(23). Epub 2019 Nov 25.

Achucarro Basque Center for Neuroscience, Science Park of the Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), 48940 Leioa, Spain.

McArdle disease, also known as glycogen storage disease type V (GSDV), is characterized by exercise intolerance, the second wind phenomenon, and high serum creatine kinase activity. Here, we recapitulate mutations in the population responsible for this disease. Traditionally, McArdle disease has been considered a metabolic myopathy caused by the lack of expression of the muscle isoform of the glycogen phosphorylase (PYGM). Read More

Med Sci Sports Exerc 2019 11;51(11):2183-2192

Institute of Bioimaging and Molecular Physiology, National Research Council, Segrate, Milan, ITALY.

: The relevance of translational medicine (bringing basic science methods "to the bed of patients") is universally recognized. Too often, however, the tools to be applied translationally are thought to derive only from the "-omics" (genomics, proteomics, transcriptomics, metabolomics, etc.) world. Read More

Clin Rheumatol 2019 Oct 1;38(10):2941-2948. Epub 2019 May 1.

Division of Rheumatology, Department of Internal Medicine, Eskişehir Osmangazi University, 26480, Eskişehir, Turkey.

Gout disease is an inflammatory arthritis that arises due to the accumulation of monosodium urate crystals (MSU) around the joints and in tissues. Clinical manifestation of metabolic diseases leading to secondary hyperuricemia most predominantly occurs in the form of gouty arthritis. Hyperuricemia and gout may develop during the course of glycogen storage diseases (GSD), particularly in GSD type I, which involves the liver. Read More

Ophthalmol Retina 2019 03;3(3):210

Department of Ophthalmology & Visual Sciences, QEII Health Sciences Centre, Halifax, Nova Scotia, Canada.

CEN Case Rep 2019 08 21;8(3):194-199. Epub 2019 Mar 21.

Department of Nephrology, Hiroshima University Hospital, 1-2-3 Kasumi, Minami-ku, Hiroshima, 7348551, Japan.

McArdle disease (glycogen storage disease type V) is a rare hereditary metabolic myopathy. It can be overlooked clinically because it often presents as chronic asymptomatic hypercreatine phosphokinasemia (hyperCKemia). However, vigorous exercise or infections can trigger severe rhabdomyolysis. Read More

Clin Investig Arterioscler 2019 Mar - Apr;31(2):89-92. Epub 2019 Feb 6.

Unidad Clínica y de Investigación en Lípidos y Arteriosclerosis, Hospital Universitario Miguel Servet, IIS Aragón, CIBERCV, Zaragoza, España; Universidad de Zaragoza, Zaragoza, España.

A 60-year-old male with familial combined hyperlipidemia, ischemic heart disease and type 2 diabetes. Since childhood, intolerance to intense exercise. The patient was diagnosed of McArdle's disease after an episode of rhabdomyolysis associated with statins as treatment after a myocardial infarction. Read More

QJM 2019 Apr;112(4):281-282

From the Department of Endocrinology, Metabolism and Nephrology, Kochi University, Kohasu, Oko-cho, Nankoku, Kochi, Japan.

Eur Radiol 2019 Jun 17;29(6):3224-3232. Epub 2018 Dec 17.

Department of Neurology, BG-University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany.

Purpose: To evaluate differences in diffusion parameters in thigh muscles in patients with glycogen storage disease type V (McArdle disease) using muscle diffusion tensor imaging (mDTI) compared to healthy controls METHODS: In this prospective study, we evaluated thigh muscles from hip to knee of 10 McArdle patients (5 female, mean age 33.7 ± 14.4 years) and 10 healthy age- and gender-matched volunteers. Read More

Rev Esp Anestesiol Reanim 2019 Mar 30;66(3):163-166. Epub 2018 Nov 30.

Servicio de Anestesiología y Reanimación, Hospital de Jerez de la Frontera, Jerez de la Frontera (Cádiz), España.

McArdle disease or type V glycogenosis is a rare metabolic myopathy consisting of muscle loss and weakness. These patients have risks associated with anaesthesia. They can present with hypoglycaemia, rhabdomyolysis, acute renal failure, and electrolyte changes. Read More

J Cachexia Sarcopenia Muscle 2019 02 21;10(1):35-53. Epub 2018 Nov 21.

Institut NeuroMyoGene (INMG), Université Lyon 1, CNRS UMR 5310, INSERM U 1217, Lyon, France.

Background: The protein kinase mechanistic target of rapamycin (mTOR) controls cellular growth and metabolism. Although balanced mTOR signalling is required for proper muscle homeostasis, partial mTOR inhibition by rapamycin has beneficial effects on various muscle disorders and age-related pathologies. Besides, more potent mTOR inhibitors targeting mTOR catalytic activity have been developed and are in clinical trials. Read More

Ophthalmology 2019 02 11;126(2):320-322. Epub 2018 Oct 11.

UCL Institute of Ophthalmology, University College London, London, UK; Genetics and Medical Retina Services, Moorfields Eye Hospital, London, UK.

J Neuromuscul Dis 2018;5(3):353-357

Department of Rehabilitation, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, The Netherlands.

Background: Exertional myalgia and cramps of the limb and trunk muscles are typical in McArdle disease, but mastication and oral motor limitations have not been systematically investigated before.

Objective: Determine the reported prevalence and characteristics of limitations on oral motor activities, mastication, swallowing, and other oral motor activities in patients with McArdle disease.

Methods: An observational study was carried out in 28 patients using a standardised questionnaire on mastication and oral motor function. Read More

Hum Mutat 2018 10 26;39(10):1338-1343. Epub 2018 Jul 26.

Grupo de Investigación de Enfermedades Mitocondriales y Neuromusculares, Instituto de Investigación Hospital 12 de Octubre (i+12), Madrid, Spain.

McArdle disease is a disorder of muscle glycogen metabolism caused by mutations in the PYGM gene, encoding for the muscle-specific isoform of glycogen phosphorylase (M-GP). The activity of this enzyme is completely lost in patients' muscle biopsies, when measured with a standard biochemical test which, does not allow to determine M-GP protein levels. We aimed to determine M-GP protein levels in the muscle of McArdle patients, by studying biopsies of 40 patients harboring a broad spectrum of PYGM mutations and 22 controls. Read More

Semin Pediatr Neurol 2018 07 1;26:50-51. Epub 2017 Apr 1.

Section of Genetics and Metabolism, Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, AR. Electronic address:

We present the case of a young woman with worsening attacks of muscle pain and rhabdomyolysis beginning at age 14. Initial metabolic testing and electromyography revealed findings of a nonspecific myopathy. Diagnostic options were discussed among the members of a neurogenetics clinic team. Read More

J Inherit Metab Dis 2018 11 20;41(6):1027-1035. Epub 2018 Jun 20.

Grup de Recerca en Malalties Neuromusculars i Neuropediatriques, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Campus Can Ruti, Universitat Autònoma de Barcelona, Badalona, Barcelona, Spain.

McArdle disease is an autosomal recessive condition caused by deficiency of the PYGM gene-encoded muscle isoform of glycogen phosphorylase. Some cases of "manifesting" heterozygotes or carriers (i.e. Read More

Acta Neurol Scand 2018 Oct 10;138(4):301-307. Epub 2018 May 10.

Physiology Department- EA 4324, CHRU Cavale Blanche, Brest, France.

Objective: As exercise intolerance and exercise-induced myalgia are commonly encountered in metabolic myopathies, functional screening tests are commonly used during the diagnostic work-up. Our objective was to evaluate the accuracy of isometric handgrip test (IHT) and progressive cycle ergometer test (PCET) to identify McArdle disease and myoadenylate deaminase (MAD) deficiency and to propose diagnostic algorithms using exercise-induced lactate and ammonia variations.

Methods: A prospective sample of 46 patients underwent an IHT and a PCET as part of their exercise-induced myalgia and intolerance evaluation. Read More

Muscle Nerve 2018 09 17;58(3):456-459. Epub 2018 May 17.

Neurological Clinic Bergmannsheil, Ruhr-University Bochum, Bochum, Germany.

Introduction: The aim of this study was the label-free identification of distinct myopathological features with coherent anti-Stokes Raman scattering (CARS) imaging, which leaves the sample intact for further analysis.

Methods: The protein distribution was determined without labels by CARS at 2,930 cm and was compared with the results of standard histological staining.

Results: CARS imaging allowed the visualization of glycogen accumulation in glycogen storage disease type 5 (McArdle disease) and of internal nuclei in centronuclear myopathy. Read More

J Inherit Metab Dis 2018 11 28;41(6):1037-1042. Epub 2018 Mar 28.

GENUD Toledo Research Group, Universidad de Castilla-La Mancha, Avda Carlos III s/n, 45071, Toledo, Spain.

Introduction: McArdle disease is an inborn disorder of muscle glycogen metabolism that produces exercise intolerance, and has been recently associated with low values ​​of lean mass (LM) and bone mineral content (BMC) and density (BMD) in affected adults. Here we aimed to study whether this bone health problem begins in childhood.

Methods: Forty children and adolescents were evaluated: 10 McArdle disease and 30 control children (mean age of both groups, 13 ± 2y). Read More

Gynecol Endocrinol 2018 Sep 21;34(9):736-739. Epub 2018 Mar 21.

a Department of Gynecology and Obstetrics, Division of Obstetrics and Feto-maternal Medicine , Medical University of Vienna , Vienna , Austria.

McArdle disease or glycogen storage disease (GSD) type V is a rare autosomal recessive inherited disorder in skeletal muscle metabolism leading to exercise intolerance, muscle cramps and in some cases to rhabdomyolysis and acute renal failure due to elevated serum myoglobin levels. Albeit the uterine smooth muscle is not affected, pregnancy and delivery can be physically strenuous and may require specific anesthesiologic care. However, data on pregnancy progress and outcome and on special implications linked to anesthesia in women with McArdle's disease is scarce, thus posing a challenge to pre- and peripartal management. Read More

BMJ Case Rep 2018 Feb 1;2018. Epub 2018 Feb 1.

Department of Nephrology, Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal.

We present a case of a 51-year-old man who went to the emergency department after an almost-drowning episode, presenting with muscular weakness, myalgia and dark urine. Laboratory data showed a severe rhabdomyolysis (creatine kinase 497 510 U/L). Despite aggressive fluid therapy, an oliguric acute kidney injury was established with temporary need of haemodialysis. Read More

Eur J Hum Genet 2018 05 25;26(5):758-764. Epub 2018 Jan 25.

Harry Perkins Institute of Medical Research, QEII Medical Centre, QQ Block, Nedlands, WA, 6009, Australia.

Name of the disease (synonyms) McArdle disease (glycogenosis type V; glycogen storage disease V (GSDV); PYGM deficiency; muscle glycogen phosphorylase deficiency; myophosphorylase deficiency). OMIM# of the disease #232600. Name of the analysed genes or DNA/chromosome segments Muscle glycogen phosphoryalse (PYGM). Read More

J Physiol 2018 03 14;596(6):1035-1061. Epub 2018 Feb 14.

Research Institute of the Hospital 12 de Octubre ('i+12'), Madrid, Spain.

Key Points: Although they are unable to utilize muscle glycogen, McArdle mice adapt favourably to an individualized moderate-intensity endurance exercise training regime. Yet, they fail to reach the performance capacity of healthy mice with normal glycogen availability. There is a remarkable difference in the protein networks involved in muscle tissue adaptations to endurance exercise training in mice with and without glycogen availability. Read More

JBJS Case Connect 2017 Jul-Sep;7(3):e49

1OhioHealth Doctors Hospital, Columbus, Ohio2OhioHealth Orthopedic Trauma and Reconstruction Surgeons, Grant Medical Center, Columbus, Ohio.

Case: McArdle disease, a glycogen storage disorder, often manifests as exercise intolerance secondary to muscle ischemia. Few authors have reported on rhabdomyolysis or compartment syndrome following inciting events among patients with McArdle disease. We present the case of a 40-year-old woman who developed spontaneous compartment syndrome of the right forearm and subsequently underwent emergency fasciotomy. Read More

Med Sci Sports Exerc 2018 Jan;50(1):3-10

GENUD Toledo Research Group, Universidad de Castilla-La Mancha, Toledo, SPAIN.

Introduction-purpose: McArdle disease (muscle glycogen phosphorylase deficiency) is a genetic condition associated with exercise intolerance, but how it affects lean mass (LM) and bone mineral content (BMC) and density (BMD) in patients is unknown. We compared these variables between McArdle patients and age-/sex-matched healthy controls and assessed their potential association with physical activity levels in patients.

Methods: A case-control, cross-sectional design was used to examine LM, BMC, and BMD by using dual-energy x-ray absorptiometry in 136 young adults of both sexes (36 McArdle patients (33 ± 15 yr) and 103 controls (34 ± 11 yr)). Read More

Clin Exp Optom 2018 05 26;101(3):412-415. Epub 2017 Nov 26.

Ophthalmology Macular Service, Belfast Health and Social Care Trust, Belfast, UK.

Mol Genet Metab 2018 01 21;123(1):21-27. Epub 2017 Nov 21.

Copenhagen Neuromuscular Center, Department of Neurology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark. Electronic address:

Background: McArdle disease (glycogen storage disease type V) is an inborn error of skeletal muscle metabolism, which affects glycogen phosphorylase (myophosphorylase) activity leading to an inability to break down glycogen. Patients with McArdle disease are exercise intolerant, as muscle glycogen-derived glucose is unavailable during exercise. Metabolic adaptation to blocked muscle glycogenolysis occurs at rest in the McArdle mouse model, but only in highly glycolytic muscle. Read More

BMC Genomics 2017 Nov 14;18(Suppl 8):819. Epub 2017 Nov 14.

Instituto de Investigación Hospital 12 de Octubre (i+12), Madrid, Spain.

Background: We recently described the genotype/phenotype features of all Spanish patients diagnosed with McArdle disease as of January 2011 (n = 239, prevalence of ~1/167,000) (J Neurol Neurosurg Psychiatry 2012;83:322-8). Several caveats were however identified suggesting that the prevalence of the disease is actually higher.

Methods: We have now updated main genotype/phenotype data, as well as potential associations within/between them, of all Spanish individuals currently diagnosed with McArdle disease (December 2016). Read More

Neuromuscul Disord 2017 12 14;27(12):1143-1151. Epub 2017 Sep 14.

Research Group on Neuromuscular and Mitochondrial Diseases, Vall d'Hebron Research Institute, Universitat Autònoma de Barcelona, CIBERER, Barcelona, Catalonia, Spain.

Neuromuscul Disord 2017 Nov 16;27(11):997-1008. Epub 2017 Jun 16.

Department of Neurology, Istanbul University, Istanbul Medical Faculty, Istanbul, Turkey. Electronic address:

This study aimed to identify PYGM mutations in patients with McArdle disease from Turkey by next generation sequencing (NGS). Genomic DNA was extracted from the blood of the McArdle patients (n = 67) and unrelated healthy volunteers (n = 53). The PYGM gene was sequenced with NGS and the observed mutations were validated by direct Sanger sequencing. Read More

Stem Cell Res 2017 08 28;23:188-192. Epub 2017 Jul 28.

Departamento de Bioquímica, Facultad de Medicina, Universidad Autónoma de Madrid, Spain; Instituto de Investigaciones Biomédicas "Alberto Sols", (UAM-CSIC) Madrid, Spain; Centro de Investigación Biomédica en Red (CIBERER), Madrid, Spain; Instituto de Investigación Sanitaria Hospital 12 de Octubre (i+12), Madrid, Spain. Electronic address:

Human iPSC line IISHDOi001-A was generated from fibroblasts of a patient with McArdle disease harbouring the mutation, c.148C>T; p.Arg50Ter, in the PYGM gene. Read More

J Clin Neurosci 2017 Dec 5;46:62-64. Epub 2017 Sep 5.

Department of Neurology, Mayo Clinic, Rochester, MN, United States. Electronic address:

A 35year-old male developed myalgias after moving furniture and was hospitalized with acute renal failure and rhabdomyolysis requiring hemodialysis. He then had several generalized tonic-clonic seizures. Brain MRI showed findings of posterior reversible encephalopathy syndrome (PRES). Read More

Mol Genet Metab 2017 11 25;122(3):117-121. Epub 2017 Aug 25.

Department of Neurology & Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA; Neuromuscular Center, Institute for Exercise and Environmental Medicine of Texas Health Presbyterian Hospital, Dallas, USA; North Texas VA Health Care System, Dallas, TX, USA. Electronic address:

Objective: We investigated metabolism and physiological responses to exercise in an 18-year-old woman with multiple congenital abnormalities and exertional muscle fatigue, tightness, and rhabdomyolysis.

Methods: We studied biochemistry in muscle and fibroblasts, performed mutation analysis, assessed physiological responses to forearm and cycle-ergometer exercise combined with stable-isotope techniques and indirect calorimetry, and evaluated the effect of IV glucose infusion and oral sucrose ingestion on the exercise response.

Results: Phosphoglucomutase type 1 (PGM1) activity in muscle and fibroblasts was severely deficient and PGM1 in muscle was undetectable by Western blot. Read More

J ECT 2017 12;33(4):e36-e37

Department of Anesthesiology, Sainte Marguerite University Hospital, Marseille, France Department of Psychiatry, Sainte Marguerite University Hospital, Marseille, France Department of Anesthesiology, Sainte Marguerite University Hospital, Marseille, France Department of Psychiatry, Sainte Marguerite University Hospital, Marseille, France

Proc Natl Acad Sci U S A 2017 08 17;114(31):8402-8407. Epub 2017 Jul 17.

Howard Hughes Medical Institute, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114;

McArdle disease and mitochondrial myopathy impair muscle oxidative phosphorylation (OXPHOS) by distinct mechanisms: the former by restricting oxidative substrate availability caused by blocked glycogen breakdown, the latter because of intrinsic respiratory chain defects. We applied metabolic profiling to systematically interrogate these disorders at rest, when muscle symptoms are typically minimal, and with exercise, when symptoms of premature fatigue and potential muscle injury are unmasked. At rest, patients with mitochondrial disease exhibit elevated lactate and reduced uridine; in McArdle disease purine nucleotide metabolites, including xanthine, hypoxanthine, and inosine are elevated. Read More

Neuromuscul Disord 2017 Sep 3;27(9):852-855. Epub 2017 May 3.

MRC Centre for Neuromuscular Diseases and Department of Molecular Neuroscience, University College London Institute of Neurology and National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK; Dubowitz Neuromuscular Centre, Great Ormond Street Hospital, London WC1N 3JH, UK.

Diagnosis of McArdle disease is frequently delayed by many years following the first presentation of symptoms to a health professional. The aim of this study was to investigate the importance of misdiagnosis in delaying diagnosis of McArdle disease. The frequency of misdiagnosis, duration of diagnostic delay, categories of misdiagnoses and inappropriate medical interventions were assessed in 50 genetically confirmed patients. Read More

J Physiol 2017 05;595(9):2991-2992

Universidad Pablo de Olavide, Sevilla, Spain.

J Physiol 2017 05;595(9):2993-2994

Australian Institute of Sport, Canberra, and Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, Australia.

Muscle Nerve 2018 Jan 21;57(1):157-160. Epub 2017 Mar 21.

Département de Neurologie, Hôpital de Hautepierre, Hôpitaux Universitaires de Strasbourg, 1 Avenue Molière, 67098, Strasbourg, France.

Introduction: McArdle disease is a glycogen storage disease caused by mutations in the PYGM gene encoding myophosphorylase. It manifests classically with childhood-onset exercise-induced pain.

Methods: We report the characteristics of 2 unrelated patients with a new homozygous mutation of the PYGM gene. Read More

Continuum (Minneap Minn) 2016 Dec;22(6, Muscle and Neuromuscular Junction Disorders):1829-1851

Purpose Of Review: Metabolic myopathies are genetic disorders that impair intermediary metabolism in skeletal muscle. Impairments in glycolysis/glycogenolysis (glycogen-storage disease), fatty acid transport and oxidation (fatty acid oxidation defects), and the mitochondrial respiratory chain (mitochondrial myopathies) represent the majority of known defects. The purpose of this review is to develop a diagnostic and treatment algorithm for the metabolic myopathies. Read More

Am J Case Rep 2016 Nov 30;17:905-908. Epub 2016 Nov 30.

MRC Centre for Neuromuscular Diseases and Division of Neuropathology, University College London Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, United Kingdom.

BACKGROUND McArdle disease is a glycogen storage disorder mainly characterized by exercise intolerance. Prolonged muscle contracture is also a feature of this condition and may lead to rhabdomyolysis (RM), which is a serious event characterized by acute skeletal muscle damage.  CASE REPORT A 44-year-old female patient presented with an acute contracture of the posterior neck muscles, causing severe nuchal rigidity. Read More

Muscle Nerve 2017 06 16;55(6):916-918. Epub 2016 Dec 16.

Division of Exercise Science and Sports Medicine, Department of Human Biology, University of Cape Town, PO Box 115, Newlands, 7725, South Africa.

Introduction: McArdle disease is a metabolic myopathy that presents with exercise intolerance and episodic rhabdomyolysis. Excessive muscle recruitment has also been shown to be present during strenuous exercise, suggesting decreased power output. These findings could potentially be explained by either impaired contractility, decreased fiber size, or altered fiber type proportion. Read More

Genet Med 2016 11 25;18(11):1128-1135. Epub 2016 Feb 25.

Laboratorio de Enfermedades Mitocondriales y Neuromusculares, Hospital 12 de Octubre, Madrid, Spain.

Purpose: McArdle disease is a metabolic disorder caused by pathogenic mutations in the PYGM gene. Timely diagnosis can sometimes be difficult with direct genomic analysis, which requires additional studies of cDNA from muscle transcripts. Although the "nonsense-mediated mRNA decay" (NMD) eliminates tissue-specific aberrant transcripts, there is some residual transcription of tissue-specific genes in virtually all cells, such as peripheral blood mononuclear cells (PBMCs). Read More

Neurol Res 2016 Dec 20;38(12):1052-1055. Epub 2016 Oct 20.

a Department of Neurology , Martin-Luther-University Halle-Wittenberg , Halle (Saale) , Germany.

During physical activity in McArdle patients, little or no lactate is released in the skeletal muscle. However, excessive ammonia production has frequently been reported in these patients. Production of ammonia is catalysed by AMP deaminase (AMPD) and adenylate kinase (AK). Read More